1. Field of The Invention
The invention relates to polyester resins and more particularly to polyester resins end-capped, extended or branched with silane esters.
2. Brief Description of the Prior Art
Polyester resins are a well-known class of synthetic polymeric resins, generally prepared by the reaction of a polyhydric alcohol with a polyacid; see for example U.S. Pat. No. 3,989,672. Although such polyester resins have been found to be thermoplastically moldable under a broad range of molding conditions, some polyester resin compositions are not suitable for use in all desired applications because they inherently lack certain desired physical properties such as a particular intrinsic viscosity, weight average molecular weight range and like properties. The present invention provides a means for controlling molecular weights and intrinsic viscosities, while minimizing affects on other desired properties of the basic polyester resin. Thus, by the means of the present invention polyester resin chains can be terminated, extended and/or branched to control molecular weights and intrinsic viscosities.